The present invention is directed to an adjustable pin drill guide and methods for inserting pins into adjacent vertebral bodies for use during a spinal surgical procedure.
U.S. patent application Ser. No. 11/439,808 (“the '808 application”), which was filed on May 20, 2006 and which is hereby incorporated by reference herein, describes the placement of pins in adjacent vertebral bodies using a pin drill guide. As described in the '808 application, after removal of disc tissue between adjacent vertebral bodies and placement of midline score marks and tack openings in adjacent vertebral bodies, pins are attached to the anterior faces of the bodies, for use in guiding other instruments during the surgical procedure disclosed therein. The pins are inserted using a pin drill guide, as shown as element 194 in at least FIGS. 11A-11D of the '808 application, that is partially inserted into the dissected disc space.
Specifically, referring to FIG. 45 of the '808 application, a head or extension 214 at a distal end 196 of pin drill guide 194 is inserted into the disc space between the vertebral bodies until vertebral body stops 222 and 224 abut against the anterior faces of the superior and inferior vertebral bodies. The pin drill guide is preferably aligned with the midline of the vertebral bodies (e.g., as marked by the score line markings) prior to this insertion. At this stage, one of the openings 210 or 212 in a main body 204 of pin drill guide 194 is preferably in alignment with the superior vertebral body and another one of the openings is in alignment with the inferior vertebral body. Referring to FIG. 46 of the '808 application, with pin drill guide 194 in place, holes are drilled in the superior and inferior vertebral bodies using a drill bit and the pins are placed in the holes.
Using pin drill guide 194 as described above does not allow for size variations of dissected disc space. That is, the pin drill guide is only applicable for a specific size of dissected disc space. Thus, multiple sizes of pin drill guides 194 may be needed for various patients. Accordingly, a need exists to overcome, inter alia, the above stated limitations.